Rotary pump



Aug. 21, 1928.

E. J. WENDELL ROTARY PUMP Filed Feb. 15, 1926 Patented 1 mg. .21, 1928.

Uhli'iifi STATES 1,681,796 PATENT orrics.

EVllItT J. WENDELL, OF \VAYNE, PENNSYLVANIA.

ROTARY PUMP.

Application filed February This invention relates to rotary pumps of the type employing coopcra ing toothed rotors, and the principal object of the invention is to provide anovel and improved construction permitting a practical standardization of parts for all pumps within certain limits of capacity ant generally increasing the operating efficiency of pumps of the type involved.

In the attached drawing I have illustrated in transverse section sufficient of a. pump to illustrate the pre ent invention.

Nith reference to the drawing, 1 represents that part of the pump casing which houses the cooperating rotors 2 and 3, these rotors being carried by shafts i and 5 which are geared together in well known manner. Each of the rotors carries in the present instance two teeth 6, 6, and each rotor also has a corresponding number of recesses 7, 7 arranged to register with the teeth of the other rotor as the two simultaneously revolve. Intermediate the teeth and rec sse the rotors are in peripheral contact and, a illustrated, the teeth 6 and recesses 7 ar cooperatively formed to maintain the water seal. etween the rotors. Each of the teeth, which are removably set in the rotors, is provided with a blade 8, the latter occupying a slot in the outer faces of the teeth, and being retained therein by a flange 9 occupying a corresponding recess in the side of the slot which the blade occupies. Provision is made for limited free radial movement of the blade, and springs 10 in the rotors extend through the bases of the teeth and resiliently retain the blades in an extended position in which the outer edges thereof wipe the walls of the pump chamber, as clearly illustrated, and seal the joint 3etween the outer ends of the blades and the said walls. The rotors revolve in the directions of the arrows, and accordingly the fluid. being pumped enters the chamber through the port 11 and is discharged through the port 12. The operation of this type of pump is well understood in the art.

It will be noted that the teeth 6 and recesses 7 are so formed that the cooperating or contacting portions of their surfaces are comparatively small. being restricted on the tooth to the areas designated by the reference numeral 13 and in the recesses to those designated by the reference numeral 1%.

These surfaces may be formed in the usual manner, the curve of the surfaces 13 being 15, 1926. Serial No. 88,307.

e agate of the surfaces 14, and the lat- L51 being formed, as indicated, on planes 1 a to the rotor. As clearly illustrated also, the re is formed to give ample clearance to the extended, comparatively narrow blade 8.

The arrangement is such that by regulat ng the height of the blade, as for example by cutting away outer portions thereof, and by correspondingly varying the thickness of the chamber wall, either by the addition of suitable liners or by cutting the walls down from a maximum thickness, the capacity of the pump may be varied, within obvious limits, as desired. Assuming for example that the teeth 6 are originally of the dimensions shown in full lines, the casing 1 also being as illustrated in full lines, and it is 1 ed to give the pump a capacity less than may be removed, for example, to t 1e broken line designated by the reference numeral 16, and a liner 17 of corresponding thickness attached to the inner face of the rotor chamber, as clearly illustrated. This ms the effect of reducing the effective space swept by the teeth between the walls of the casing and the faces of the rotors and correspondingly reduces the capacity of the pump. A. still further reduction in capacity maybe accomplished in the same manner, by further cutting down the tooth to the line 18 and adding a second liner 19 of thickness corresponding to the second reduction in height of the tooth or bv a sinliner replacing the liner 17 and 0f the required additional thickness. Obviously the height of the blade 8 should be corrospondingly r duced in each instance. In practice, however, the blades 8 will be proferably formed originally of a maximum height and the walls of the casing of a maximum thickness, both being cut down as required.

It will be noted that the stated reductions in the height of the tooth '6 do not in any way affect the working faces 13 and 1.4:, the rotors functioning as originally, and the only effect being the variation in the capacity of the pump.

t will further be noted that the bases of the teeth 6 and the sockets 20 in which they are seated are. formed to correspond accurately with the formation of the outer part of the recesses 7, thus providing for the use of a single milling cutter in form- Ill!) the sides of the said sockets. The material manufacturing advantage Will be obvious.

I have found this form oftooth to give an extremely uniform outflow and to be both highly el'lioient and durable.

I claim:

In a pump, the combination with a housing, of a pair of peripherally-contacting r0 tors mounted in said housing and each having av plurality of longitudinal sockets teeth mounted in said sockets and having projecting vanes adapted to sweep the surfaces of the rotor chamber, said rotor having also a plurality of longitudinal recesses adapted to register with and receive the. teeth of the opposite rotor as the two rotors simultaneously revolve, and having their outer part corresponding in form With said sockets.

. EVERT J. NENDELL. 

